This invention relates to a bus duct system in which bus bars for carrying electric current are mounted and enclosed within sections of bus duct housing. Such bus duct systems include means for connecting tap-off units to the bus bars. Existing systems have relatively complex and expensive structures for providing tap-off connections, including supporting, bracing and mounting means at and adjacent to the sections of the bus duct in which the tap-off connection is made. In accordance with the present invention, simplified bracing members are provided as well as simplified means for securing bracing members to the bus duct. The bracing members are also located in a position to lend support to the bus bars when tap-off units are being connected thereto. The access openings are provided with simplified sliding doors, for which mounting means and track means are formed as integral parts of the bus duct walls and the cooperatively mounted bracing members.
It is an object of the present invention to provide a bus duct system which combines a bracing molding and a sliding shutter to allow, at low cost, access to the bus bars for attachment, for example, of a tap-off box.
It is a further object of the present invention to provide a bus duct system which minimizes the number of different joints required and which simplifies the construction of the joints.
According to one aspect of the present invention there is provided a bus duct system comprising an elongate section forming a housing having flat bus bars therein, means for supporting and bracing the bus bars in the housing at a number of spaced apart positions in the section and at least one sliding shutter located adjacent at least one of said means to allow access to the bus bars.
According to a second aspect of the present invention there is provided a bus duct system comprising a plurality of elongate sections forming a housing for bus bars, a number of different joints joining said sections together, the joints being formed from a number of component parts wherein at least some of said component parts are common to a number of different joints.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: